1. Field of the Invention
The present invention relates to improvements in devices for inserting cylindrical insert members in the open ends of relatively thick-walled plastic tubing. In particular, the present invention relates to a hand held, portable tool for inserting the cylindrical inserts into open ends of plastic tubing.
2. State of the Art
In the manufacturing of integrated circuit chips, it has been necessary because of cleanliness requirements and the corrosive nature of the chemicals used to employ fluid handling system, including chemical pumps and piping, that are formed from chemically resistant plastic components such as fluoroplastic materials, including polytetrafluoroethylene and perfluoroalkoxy. Tubing and fittings must be made of the plastic components so that the liquids being conveyed come in contact with only components that are mad of chemically resistant plastic material. Tubing and fittings must be capable of high temperatures and high pressures that are commonly used in the chemical systems employed in industries requiring high-purity fluid handling.
To withstand pressure and temperature requirements, the tubing is relatively thick-walled, having thicknesses of about 3/64 inch for 1/4 inch outside diameter tubing up to about 1/8 inch for tubing having an outside diameter of 3/8 inch or greater. Flare fittings have been used in the past wherein the ends of the tubing are heated and flared. Recently, improved fittings have been developed which utilize so-called cold flaring. In such fittings, a cylindrical insert member is inserted into the open end of the tube. The insert member has an outside diameter that is larger than the inside diameter of the tube in which it is to be inserted. In addition, an enlarged torus is provided at the end of the insert member which is to be inserted in the tube. The torus expands the open end of the tube to make a flare in the tube.
The insert is forced into the end of the tube at ambient temperature, and the fittings have been referred to as cold-insert flare fittings. The fittings have found wide use in the manufacture of semiconductor and other electronic products. One inherent problem with such fittings is the large force necessary to push the insert member into the end of the relatively thick-walled tubing. Large, bulky, bench-mounted apparatus is presently used to force the insert member into the end of the tubing. However, such bulky, bench-mounted apparatus is not easily moved, and thus when maintenance is needed on a fitting in an operating areas such as within a wet bench production facility in the semiconductor industry, the fittings and tubing must be removed and carried to the nearest bench-mounted apparatus for repair. I would be highly desirable to have portable, hand held and hand operated apparatus that could be moved to the site of the tubing installation to allow maintenance to be conducted at the site of the installation. Large savings in downtime and expense could be realized if repair and maintenance could be accomplished quickly at the site of the tubing installation instead of removing the tubing and fittings to a remote area for repair and maintenance.